This application is related to and claims priority from Japanese Patent Applications No. Hei. 11-230796 filed on Aug. 17, 1999, the contents of which are hereby incorporated by reference.
1. Field of the Invention
The present invention relates to a vehicle air conditioner having a front foot air outlet for blowing air toward a front foot area of a passenger compartment and a rear foot air outlet for blowing air toward a rear foot area of the passenger compartment. In the vehicle air conditioner, a ratio between an air amount blown toward the front foot area and an air amount blown toward the rear foot area is possible to be adjusted.
2. Description of Related Art
In a conventional vehicle air conditioner, an air amount blown toward a front foot area is generally set to be larger than an air amount blown toward a rear foot area so that air-conditioning performance for a front seat side of the passenger compartment is improved preferentially. For adjusting the air amount blown toward the rear foot area, a guide plate for restricting an air flow is provided at an inlet portion of a rear foot passage. However, in this case, because an air passage resistance is increased due to the guide plate, an entire air amount blown toward the front and rear foot areas becomes smaller, and heating capacity of the passenger compartment is decreased. Further, by an air flow disturbance due to the guide plate, air-blowing noise may be increased.
For increasing the entire air amount blown toward the front and rear foot areas, an opening area of a front air outlet may be simply increased. However, actually, the shapes of front and rear air outlets are determined from a vehicle structure, and are difficult to be changed.
In view of the foregoing problems, it is an object of the present invention to provide a vehicle air conditioner in which a ratio between an air amount blown toward a front foot area and an air amount blown toward a rear foot area is simply adjusted.
According to the present invention, in a vehicle air conditioner, an air passage of an air conditioning case has an upstream foot passage and a downstream foot passage which are provided at a downstream air side of a heating heat exchanger in such a manner that the downstream foot passage directly communicate with the upstream foot passage at a downstream side of the upstream foot passage. The air conditioning case has a first front foot air outlet communicating with the upstream foot passage, a second front foot air outlet communicating with the downstream foot passage and being provided at a position adjacent to the first front foot air outlet, and a rear foot air outlet provided at a most downstream position of the downstream foot passage. Further, the second front foot passage is provided in such a manner that air is always blown from the second front foot air outlet when air is blown from the first front foot air outlet. Thus, warm air flowing into the downstream foot passage is branched into an air flow toward the rear foot air outlet and an air flow toward the second front foot air outlet, to be blown toward a front lower side and a rear lower side of a passenger compartment. Accordingly, by adjusting an opening area of the second front foot air outlet, a ratio between an entire air amount blown toward the front lower side and an air amount blown toward the rear lower side can be readily adjusted. Further, when the opening area of the second front foot air outlet is adjusted, only the ratio of the air amount blown toward the rear foot area is changed, but an air flow resistance in the foot passage is not increased. As a result, even when the opening area of the second front foot air outlet is changed, an entire air amount blown into the passenger compartment from the first and second front foot air outlets and the rear foot air outlet is not changed, and heating capacity for the passenger compartment is maintained. Further, because the air flow resistance in the foot passage is not increased, it can prevent air-blowing noise from being reduced. Due to the second front foot air outlet, the air amount blown toward the front lower side is readily increased.